Sealing element for fluid-pressure containers



Dec. 25, 1934.

H. KQESTE R SEALING ELEMENT FOR FLUID PRESSURE CONTAINERS Filed Nov. 29, 1935 IIIIIIIVIJ'IIIIIIIIIIIIA INVENTOR HERM/j /v K055 rm ATTORNEY jiv T iv STATES Patented Dec. 25, 1934 PATEN 'OFmE:

' 1,985,733 SEALING ELEME T FOR FLUID-PRESSURE CONTAINERS Herman Koester, Waterbury, Conn, assignor to The Bristol Company, Waterbury, Co'nn., a corporation of Connecticut Application November 29, 1933, Serial No. 700,333 8 Claims. (01. 2973) :-Th6 invention relates to means for i sealing a container forfiuids under pressure, for example, metal thermometerbulbs adapted to contain a volatile or expansible fluid and to whichvessel is to be connected a capillary tube placing the bulb inucommunication with a suitable, measuring instrument. i

In the use of these bulbs, it has been found expedient to form the same of a section of drawn tubing, having its one end closed and its other normally open'but adapted to "be closed by a suitableplug or bushing of metal which is soldered or brazedginto place. This plug, also, provides the connection for the capillary tube which is arranged to pass through a longitudinal opening or duct of the plug, and is, in turn, sealed to the latter into its final position.

,In forming these plugs from metal, it has been customary to-employ either a casting or rolled or drawn bar stock, the plug being formed to shape in, .a lathe and subsequently assembled to the fluid-pressure containing vessel as hereinbeforei This I have found to be due, in the case of rolled or drawn stock, to pipes or striae in the mass of the metal, whosegeneral direction is determined bythe asymmetric treatment. These inclusions, notwithstanding the rolling or drawing operations, prevent a complete seal by the plug; and under the high pressures involved, permit a seepage of the volatile contents of the vessel through the exceedingly small interstices. In the case of .cast plugs, the natural porosity of thecasting, and possibleblow-holes in the metal, may result in similarleakage, so that a leak-proof construction cannotthereby be assured.

Thepreseht invention has for an object the provision of a plugor sealing element wherein this objectionable feature is eliminated.

In carrying out the invention, provision is made for a cap designed tofit over the inner end of the.

usual plug memberto be suitably secured thereto I at the rim of the cap, as well as to the bulb or like vessehsaid cap being of a'material impervious to the fluid under pressure within the vessel, :as of wrought metal such as metal pressed or rolled from sheet stock or forged. When the cap is thus placed over the plug end, any striated inclusions of the cap will then be disposed in a direction normal to the direction of the pressure exerted upon the bottom of the cap. This effectively prevents passage of the fluid through the said bottom of the cap and thus insures a leak-prooi construction of the plug for sealing the outlet of the bulb.

thermometer bulb adapted to contain avolatile or expansible fluid. The said vessel :may' be formed of drawn tubing having the one;end 11 permanently closed and open at its opposite end to provide the outlet 12. I

This outlet is designed to be closed bya suit-P.

able plug or sealing element comprisingthe body portion 13 having thelongitudinal axial. duct 14 extending therethrough; The plugmay also be provided with a flanged section 15 and a threaded outer end 16 to provide attachment between the plug and suitable flttingsor fixtures (not'shown) for connection of the bulb in position .for use. A capillary tube 20, Fig. 2, isde-' signed to pass through the duct 14 in the usual manner to connect the interior .of the bulb 10. with a suitable measuring instrument or the like (not shown), it being understood that the inner end of the plug fits within theoutlet 12 and that the capillary tube will project into the space of the said bulb, all of which is well understood and forms no particular part of the present invention.

I The'present invention is concerned more especially with the provision of means for securing a leak-proof seal between the said plug andthe 10 designates a ves -v sel, as of metal, and, for example, such as a.

said capillary tube and bulb at the outlet of the latter. In accordance with the invention, the inner end of said plug is'not directly fitted. to the outlet end of the bulb as has been'the the duct 14 through the plug so as to pass the capillary tube 20 to the interior of bulb 10.

It is preferred, also, to upset inwardly the material of the bottom of the cap in the piercing of the same so that the upset portion 23 will afford excess metal to give. the opening 22 a somewhat greater axial length than the thickness of the bottom of the cap. This will simplify sealing of the capillary tube 20 to the bottom of the cap, as by soldering or brazing the same thereto. At its rim 24, the cup is to be soldered or brazed not only to the body portion 13 of the plug, but as well to the outer end of the bulb 10, the rim to this end being disposed, preferably, so as to lie slightly within the edge of the bulb 10, as indicated in Fig. 2. The seal effected thus at the three adjacent surfaces of plug, cap and bulb, is secure and tight" at this point, it being understood that the thickness of the cap Wall is such as to substantially fill the annular space between the external surface of the plug covered by the cap and the juxtaposed inner surface of the bulb.

Furthermore, it willbe noted that when the cap 21 is thusinterposed between the plug and the bulb, though the said plug may have striae within its mass, as indicated at 25, the cap 12 separating the inserted end of this plug from the interiorof the bulb 10, will prevent communication of the fluid pressure from within said interior space to these striae. Moreover, since any such striae, as indicated at 26, which might bepresent in the cap 21 would be the arrangement hereinbefore described be located parallel to the plane of the bottom of the cap, they would therefore be disposed in a direction normal to the pressure'applied to said bottom, and thus serve to render the cap bottom and'thereby the plug itself impervious to the passage of fluid contained within the bulb 10. 4

By' thus providing for the application of the pressure transversely to. any striae of the metal cap and by sealing the joints in the mannerdescribed, the closure as a whole is substantially impervious tothe fluid under the pressures developed within the bulb.

It is to be noted, als'o,that where the plug is intended for use merely to close or seal 01f the end of a vessel, the perforation provided in the cap will of course not be necessary and may be omitted, and no outlet tube will pass through the plug so that the duct thereof may also-be omitted.

. I claim: 1

1.' A sealing element for fluids under pressure, said element comprising a tubular metal body member and a wrought metal cap enclosing an end thereof to be exposed to the pressure,,with the grain of the cap in a direction substantiallynormal to said pressure. Y 7

i 2. The combination with a vessel adapted to retain a fluid under pressure, of an element comprising a hollow metal body adapted for insertion into an outlet of thevessel, and a wrought metal cap fitted over an end of the body member exposed to said pressures, said cap being sealed thereto and to the vessel. V

3. Ihe com nati n wi h. a v ss a pt to retain a fluid under pressure, of an element comprising a tubular body member adapted for insertion into an outlet of the vessel, and a metal cap fltted over the inserted end of the body member, sealed to the inserted end of the body member and to the vessel and impervious to the fluid under pressure in the direction of pressure exerted upon the cap bottom.

4. The combination withtwo tubular metal members of a sealing element for joining the same in fluid-pressure-sealed relationshipthe oneof said members being of a diameter to flt within the other and having an end inserted therein, a-metal cap secured over the inserted end, sealed at its rim to both of the said members and impervious to the fluid under pressure in the direction of the pressure exerted upon the cap bottom.

5. The combination with two tubular metal members, of a sealing element for joining the same in fluid-pressure-sealed relationshipthe one of said members being of a diameter to fit within the other and having an end inserted therein, and a cupped wrought metal cap whose side walls extend over the inserted end of the one tubular member and the bottom of the cap being exposed to pressure within the other and its rim being sealed to both members.

6. The combination with two tubular metal members, of a sealing element for joining the same in fluid-pressure-sealed relationshipthe one of said members being of a diameter to fit within the other and having an end-inserted therein, and a cupped wrought metal cap whose side 'walls extend over the inserted end of the one tubular member and the bottom of the cap being perforated with upset material therefrom extending inwardly of the cap for sealing thereat tubing adapted to pass through the inserted member into'the other member, said cap being exposed to pressure within the latter member and its rim being sealed'to both members.

7. In combination: a tubular vessel having an outlet and adapted to retain a fluid under pressure, a tubular member extending into the said outlet, tubing extending through the tubular member into the said vessel, and a wrought metal cap fitted over the inner end of the tubular member and about the tubing, the bottom of the cap being perforated to pass the tubular member and the rim of said cap being sealed to the body portion and to the vessel and the tubing at the perforation to the cap.

8. A plug for joining a capillary tube to a bulb adapted to retain a fluid under pressure, said plug comprising a metal body member adapted for external connection and having a longitudinal ductthrough which an end of the capillary tube is adapted to pass, and a cap fitting over the said end of the-body member, of wrought metal and having a bottom perforation for registry with the duct of the body member when the said cap is fitted over the end thereof, said cap being sealed at its rim to the body member and at its perforation to the capillary tube, and the plug as a whole being adapted to be sealed to the bulb at the rim of said cap.

HERMAN KOESTER. 

